According to the card that came with my black mickeys and many web sites, the black mickeys are rated for -20* F, and the white ones are rated for even colder than that, but each white boot is about a half pound heavier than the black ones (extra insulation).
I got the black ones because I didn't want the extra weight since they are heavy already, and in really frigid weather, I am in a shanty with a heater. I figured with a rating of -20* F for the black mickeys, and reviews from many owners, those should do me fine.
Any others out there with mickeys with sock recommendations? wool? 1 pair only? Cotton? Moisture-wicking socks or liners?
Thanks.